My search function is not working!
Since there are at least 3 different kinds of searches, could you be very specific about exactly what you are doing, what exists, what you expect and what you get.
Also, did you create search folders?
Normally I click on All Mail and enter an email in the search box at the top right. It will then find all my past emails sent and received to that email and list them. Now it does nothing and the results remain blank. There is no error message. There are still thousands of emails within the All Mail folder.
If you want to find email, either for sender or recipient, click the down caret next to the search box, and make sure your search option is set to one of the options indicated in the image below, and that All folders is selected.
That’s it! Great, thanks! It was that the Subject, sender etc. was not ticked for some reason.